In this research, we focus on heat treatment, specifically during the downsizing of production systems. We devise a method designed to remedy the problem of quenching for thin plates, by using a small semiconductor laser. In this report, we investigated a method to reduce the influence, deformation amount, and three–dimensional (3D) distortion error of residual stress that occurred when a laser test was performed on a metal test piece. Regarding the residual stress, the specimen was burned out by continuous scanning. Its residual stress showed a tendency to fade as the specimen was scanned at lower speeds. We found it was possible to reduce deformation by restraining the specimen with the jig, but that 3D strain error under this constrained state remained of the same order as it was in the unconstrained state. In addition, by restraining the test piece with a jig, it was possible to prevent reverse deformation (Buckling Mechanism).